August 14, 2003 was a brutally hot day in much of the northeastern U.S. The high temperatures prompted people in cities like Pittsburgh and New York to crank up the fans and the air conditioning. The electricity those appliances consumed put unusually high demands on the transmission grid, forcing power plants to work overtime. The summer heat also caused local power lines in northern Ohio to expand and physically sag, which brought them into contact with nearby trees. Sparks ensued, and the resulting short circuit shut down power locally.

An alarm should have gone off at a local utility, leading the operator to reroute the flow of power around the affected area until a repair crew could be dispatched to fix the downed wires. But that didn't happen. The alarm never sounded, and utilities across the regional grid kept sending power through the weakened area, stressing the transmission lines further. Within two hours of the short circuit, all of the power lines in Ohio cut out, triggering a chain reaction that led other regional grids to fail before operators could do anything to respond. The resulting blackout  the biggest in American history  affected 55 million people in the northeastern U.S. and Canada. Darkness fell across Times Square because the aging snarl of wires and transformers that is the U.S. electrical grid couldn't handle a hot day and a few overgrown trees.

In his new book Resilience, Andrew Zolli  the director of the global innovation network PopTech  uses the electrical grid as an example of a system that lacks just that. And in an increasingly interconnected world  financially, ecologically, politically  one in which small errors in one place can cascade into broader system failures, the ability to adapt, accommodate and bounce back is only going to become more important. From climate change to overpopulation to recessions, the threats facing the world are as unpredictable as they are varied  which is why we need to craft systems that are nimble, that can bend under stress rather than break. "If we cannot control the volatile tides of change, we can learn to build better boats," writes Zolli. "We can design  and redesign  organizations, institutions, and systems to better absorb disruption, operate under a wilder variety of conditions, and shift more fluidly from one circumstance to the next."

In Resilience  co-written with the playwright and journalist Ann Marie Healy  Zolli covers everything from global finance to psychology, but the benefits of resilience are perhaps clearest in the environmental realm. Take the electrical grid again. Here we have a century-old system that is incredibly complex and also incredibly vulnerable to outside threats. Blackouts are only the most conspicuous part of the problem and thankfully do not occur often. But the battle is fought in other, smaller ways all the time. On unusually hot days in New York City this summer, the utility ConEd has had to reduce power flow to some parts of the city simply to keep the overstressed system running. In essence, they're trading blackouts for the occasional brownout, all because the system can't take the pressure being put on it  pressure that, thanks the increasingly hot summers climate change is bringing us, will only grow. Just as the grid is vulnerable to accidents, it also has few defenses against deliberate attacks by hackers or terrorists. And this vulnerability exists despite the fact that steady electrical service has become absolutely necessary for an always-on economy. If the grid crashes today, a lot more than your lights and air conditioner will go down with it.

To Zolli, the answer is to create what he calls a "swarming grid," a smart system that's operated more like the redundant infrastructure of the Internet  initially designed in part by the military, after all, to emphasize robustness and survivability. That means a grid capable of real-time monitoring and reaction that can create a holistic picture of what's happening throughout the transmission lines. During the 2003 blackout, operators were essentially working in the dark as they tried to head off the cascading failure  and that was even before the lights went out. The grid should be able not only to sense trouble, but to anticipate it. The current system assesses bits of information with a 30-second delay, which Zolli explains is "analogous to driving a car by looking at the rearview mirror." Finally, the national grid needs to be able to decouple into a series of local grids, to lock down into isolated islands, so that a problem in, say, Ohio doesn't result in Manhattan going dark.

Not all is hopeless. Almost despite itself, the grid is getting smarter and more resilient, with information technology companies like Google applying Internet smarts to the way we generate and electricity and move it around the country. The challenge will be paying for a system that, as Zolli notes, could eventually be one hundred to one thousand times larger than the U.S. domestic Internet, with trillions of nodes and sensors embedded in it. The only thing worse than building and paying for such a system is failing to do so, because we really have no other choice . In the 21st century, disruption is going to become the new normal in ways we can't even predict. All we can do is learn to bounce back better  and Zolli's excellent book is a very good start.